采用水泥制粒的赤泥脱除水溶液中的镉离子

摘要

A novel adsorbent was prepared from granular red mud mixed with cement and its potential to be a suitable adsorbent for the removal of cadmium ions from aqueous solutions was evaluated.The wet red mud was directly mixed up with cement at different mass fractions of 2％-8％ and their properties were investigated.Based on the textural characteristics and strength,the granular red mud with 2％ addition of cement maintaining for 6 d is identified to have better properties.The batch adsorption experiments for adsorption of Cd2+ ions from solution were performed at 30,40 and 50 C at different initial concentrations under the condition of constant pH of 6.5.The equilibrium adsorption was found to increase with the increase of temperature during the adsorption process.Langrnuir adsorption isotherm model was found to match the experimental adsorption isotherm better.The kinetics of adsorption was modeled using a pseudo second order kinetic model and the model parameters were estimated.%采用湿赤泥添加水泥作为粘结剂的方法制备出一种新型粒状吸附剂材料,并评价这种粒状赤泥材料脱除水溶液中镉离子的潜力.直接向湿赤泥中添加2％-8％的水泥,研究不同水泥添加量和保养时间对粒状赤泥基吸附剂材料的粉化率和比表面积的影响.结果表明,在2％的水泥添加量下保养6d后的粒状赤泥的结构特性和强度等参数达到了较好的水平.在pH为6.5,温度分别为30、40和500C及不同Cd2+浓度溶液的条件下,进行吸附实验研究.结果表明,随着温度的升高吸附性能提高,并以此采用伪二级动力学模型进行吸附动力学模拟,得到了相关的模型参数.